FDA Panel Rejects Obesity Drug Zimulti

Experts Concerned About Possible Risks of Suicidal Thoughts in Drug Formerly Called Acomplia

June 13, 2007 -- A new weight loss drug designed for obese adults failed to win approval from an FDA advisory panel Wednesday, mainly because of fears that it can lead to depression and suicidal thoughts in some patients.

Outside experts unanimously rejected the bid of Sanofi-Aventis to market Zimulti (rimonabant) in the U.S. despite its approval in dozens of other countries. The drug was previously known as Acomplia.

"My level of concern ... is very high," says Sid Gilman, MD, a member of the panel and a professor of neurology at the University of Michigan.

"I think this is a drug that needs further understanding with respect to what it does to people's psyche," he says.

The panel's conclusion, in a 14-0 vote, throws up a major hurdle in a longtime effort by its manufacturer to market the drug in the U.S. The decision makes it unlikely that regulators will approve the drug for U.S. sales because the FDA usually follows the recommendations of its advisory panels.

Studies conducted by its manufacturer, Sanofi-Aventis, show that many obese patients can lose up to 10% of their body weight after one year on the drug. It also appears to improve blood sugar control in obese diabetes patients.

Regulatory Battle

In early 2006, the FDA was close to approving the drug, which at the time carried the brand name Acomplia.

But the agency asked the company first to study reports that the drug seemed to cause depression and suicidal thoughts and behaviors in some patients. It also asked Sanofi-Aventis to abandon the name Acomplia because regulators considered it potentially misleading to consumers.

The company responded by offering to minimize the risk by urging doctors not to use the drug in patients with a history of depression or other mental illnesses. In the process, the name Acomplia was changed to Zimulti.

Psychiatric Risk

Company officials clashed with regulators over the size of the psychiatric risk, saying that thousand of patients who took the drug had suicide rates essentially identical to the general population. Sanofi-Aventis said they'd found a 30% increase in the risk of suicidal thoughts with the drug but that in studies those thoughts almost never led to suicide attempts.

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